Switching wireless network selection modes in conjunction with selection of a wireless cell set

ABSTRACT

An access terminal may switch to a different mode of wireless network selection as a result of manual selection of a wireless cell set (e.g., a closed subscriber group) associated with one or more wireless cells. For example, if the user of an access terminal selects a closed subscriber group in a wireless network that is different than the current wireless network, the access terminal may enter a manual mode of wireless network selection, select the wireless network corresponding to the closed subscriber group, and register on a closed subscriber group cell in the selected wireless network. In addition, an access terminal may automatically switch to a different mode of wireless network selection (e.g., the prior mode) upon losing coverage of a wireless cell set. An access terminal may also automatically select a cell of a wireless cell set if the access terminal returns to a cell of the cell set within a defined period of time after losing coverage of the cell set. Furthermore, an access terminal may return to a prior wireless network upon losing coverage of a wireless cell set.

CLAIM OF PRIORITY

This application claims the benefit of and priority to commonly ownedU.S. Provisional Patent Application No. 61/110,733, filed Nov. 3, 2008;U.S. Provisional Patent Application No. 61/114,943, filed Nov. 14, 2008;U.S. Provisional Patent Application No. 61/140,588, filed Dec. 23, 2008;and U.S. Provisional Patent Application No. 61/147,415, filed Jan. 26,2009; the disclosure of each of which is hereby incorporated byreference herein.

CROSS-REFERENCE TO RELATED APPLICATION

This application is related to concurrently filed and commonly ownedU.S. patent application Ser. No. 12/609,426, entitled “SELECTION OFWIRELESS NETWORK IN CONJUNCTION WITH SELECTION OF A WIRELESS CELL SET,”the disclosure of which is hereby incorporated by reference herein.

BACKGROUND

1. Field

This application relates generally to wireless communication and morespecifically, but not exclusively, to wireless network selection.

2. Introduction

A geographic area may be served by overlapping public land mobilenetworks (PLMNs) that provide mobile cellular services. For example,different wireless network operators may deploy different PLMNsthroughout the same city. Under certain circumstances, a given accessterminal (e.g., a cell phone) may be allowed to access these differentPLMNs. Accordingly, such an access terminal may be configured to selectwhich PLMN is to be used at a given point in time.

In some cases, an access terminal may employ an automatic mode of PLMNselection. Here, the access terminal may continually monitor foravailable PLMNs and automatically switch to a new PLMN based onspecified selection criteria. In a typical case, the selection criteriacomprise a prioritized list of PLMNs that indicates the order in whichthe access terminal is to select a PLMN in the event multiple PLMNs areavailable. Other types of selection criteria may be used as well. Forexample, priority may be given to a PLMN that would currently providethe best quality of service for the access terminal.

In some cases, an access terminal may employ a manual mode of PLMNselection. For example, a list of currently available PLMNs may bedisplayed on a screen of the access terminal. The user may then selectone of the PLMNs and the access terminal switches to that PLMN. Incontrast with an automatic PLMN selection mode, in this case the accessterminal will stay on this PLMN even if other higher priority PLMNs areavailable. For example, the access terminal may stay on the selectedPLMN until a different PLMN is manually selected or until the selectedPLMN no longer provides service to the access terminal.

An access terminal also may be configured to enable a user to manuallyselect a closed subscriber group (CSG) associated with one or morewireless cells (e.g., at least one access point). In the event theselected CSG is in a different PLMN than the current PLMN, a PLMNselection procedure may be invoked in response to the selection of theCSG. In such a case, the PLMN selection procedure may not provide adesirable result.

For example, an access terminal operating in automatic PLMN selectionmode may not be able to remain camped on a selected CSG. This may be thecase because the automatic PLMN selection mode may automatically switchto another PLMN based the designated selection criteria (e.g., if abackground search procedure detects a higher priority PLMN).

In addition, an access terminal operating in manual PLMN selection modemay attempt to remain on the new serving PLMN even after the accessterminal has left the coverage area of the selected CSG cell. In theevent no suitable cell is found for the access terminal on that PLMN(e.g., the access terminal is not allowed to access any cell other thanthe cells of the selected CSG), the user will be without service. As aresult, user interaction will be required to select another PLMN.

SUMMARY

A summary of sample aspects of the disclosure follows. In the discussionherein, a reference to the term aspects may refer to one or more aspectsof the disclosure.

The disclosure relates in some aspects to switching to a different modeof wireless network (e.g., PLMN) selection as a result of manualselection of a wireless cell set (e.g., a CSG) associated with one ormore wireless cells. For example, upon manual selection of a celladvertising a CSG, an access terminal may switch to a different mode ofwireless network selection if the wireless network associated with theselected cell is different from the currently registered wirelessnetwork or a currently preferred wireless network. As a specificexample, if the user of an access terminal selects a CSG in a PLMN thatis different from the current PLMN, the access terminal may maintain arecord of the current PLMN and a record of the current mode of PLMNselection, and enter a manual mode of PLMN selection. The accessterminal may then select the PLMN corresponding to the CSG and registeron a CSG cell in that PLMN. In this way, the access terminal may be morelikely to remain on the selected PLMN since the access terminal will notbe operating in an automatic mode of PLMN selection until some laterpoint in time (e.g., in response to some other trigger).

The disclosure relates in some aspects to switching to a different modeof wireless network selection upon losing coverage of a wireless cellset. For example, upon determining that an access terminal is no longercamped on a cell of a CSG that was manually selected by the accessterminal, the access terminal may switch to a different mode of wirelessnetwork selection (e.g., the mode that was used prior to camping on theCSG). In this way, the access terminal may likely end up selecting amore appropriate network upon leaving the coverage of the CSG.

The disclosure relates in some aspects to automatically selecting a cellof a wireless cell set if an access terminal returns to a cell of thecell set within a defined period of time after losing coverage of thecell set. For example, a timer may be started upon determining that anaccess terminal is no longer camped on a cell of a CSG that was manuallyselected by the access terminal. In the event the access terminalreturns to a cell of the CSG within a defined period of time, the cellmay be automatically selected (e.g., without user interaction) forcamping by the access terminal. In this way, the access terminal mayseamlessly reestablish access to the CSG in the event the accessterminal briefly lost the coverage of the CSG.

The disclosure relates in some aspects to returning to a prior wirelessnetwork upon losing coverage of a wireless cell set. For example, upondetermining that an access terminal is no longer camped on a cell of aCSG that was manually selected by the access terminal, the accessterminal may automatically return to the PLMN that the access terminalwas on prior to camping on the CSG.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other sample aspects of the disclosure will be described inthe detailed description and the appended claims that follow, and in theaccompanying drawings, wherein:

FIG. 1 is a simplified block diagram of several sample aspects of acommunication system adapted to switch modes of wireless networkselection and wireless networks in conjunction with manual selection ofa cell set (e.g., CSG);

FIG. 2 is a flowchart of several sample aspects of operations that maybe performed to switch wireless network selection modes and wirelessnetworks in conjunction with manual selection of a cell set;

FIG. 3 is a flowchart of several sample aspects of operations that maybe performed in conjunction with switching to a different wirelessnetwork selection mode upon manual selection of a cell set on adifferent wireless network and/or upon ceasing camping on a cell set;

FIG. 4 is a simplified diagram illustrating sample non-access stratumand access stratum call flow that may be used in conjunction withperforming manual selection of a cell set on a different wirelessnetwork and switching to a different wireless network selection mode;

FIG. 5 is a flowchart of several sample aspects of operations that maybe performed in conjunction with automatically reselecting a cell set ifan access terminal returns to the cell set within a defined period oftime;

FIG. 6 is a flowchart of several sample aspects of operations that maybe performed in conjunction with automatically returning to a wirelessnetwork upon leaving coverage of a cell set;

FIG. 7 is a simplified block diagram of several sample aspects ofcomponents that may be employed in a communication node;

FIG. 8 is a simplified diagram of a wireless communication system;

FIG. 9 is a simplified diagram of a wireless communication systemincluding femto nodes;

FIG. 10 is a simplified diagram illustrating coverage areas for wirelesscommunication;

FIG. 11 is a simplified block diagram of several sample aspects ofcommunication components; and

FIGS. 12-15 are simplified block diagrams of several sample aspects ofapparatuses configured to provide switching of wireless networkselection modes and/or wireless networks as taught herein.

In accordance with common practice the various features illustrated inthe drawings may not be drawn to scale. Accordingly, the dimensions ofthe various features may be arbitrarily expanded or reduced for clarity.In addition, some of the drawings may be simplified for clarity. Thus,the drawings may not depict all of the components of a given apparatus(e.g., device) or method. Finally, like reference numerals may be usedto denote like features throughout the specification and figures.

DETAILED DESCRIPTION

Various aspects of the disclosure are described below. It should beapparent that the teachings herein may be embodied in a wide variety offorms and that any specific structure, function, or both being disclosedherein is merely representative. Based on the teachings herein oneskilled in the art should appreciate that an aspect disclosed herein maybe implemented independently of any other aspects and that two or moreof these aspects may be combined in various ways. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, such an apparatusmay be implemented or such a method may be practiced using otherstructure, functionality, or structure and functionality in addition toor other than one or more of the aspects set forth herein. Furthermore,an aspect may comprise at least one element of a claim.

FIG. 1 illustrates several nodes of a sample communication system 100(e.g., a portion of a communication network). For illustration purposes,various aspects of the disclosure will be described in the context ofone or more access terminals, access points, and network nodes thatcommunicate with one another. It should be appreciated, however, thatthe teachings herein may be applicable to other types of apparatuses orother similar apparatuses that are referenced using other terminology.For example, in various implementations, access points may be referredto or implemented as base stations or eNodeBs, access terminals may bereferred to or implemented as user equipment or mobiles, and so on.

Access points in the system 100 provide one or more services (e.g.,network connectivity) for one or more wireless terminals that may beinstalled within or that may roam throughout a coverage area of thesystem 100. For example, at various points in time, the access terminal102 may connect to an access point 104, an access point 106, or someother access point (not shown). Each access point in the system 100 maycommunicate with one or more network entities (represented, forconvenience, by network nodes 108 and 110) to facilitate wide areanetwork connectivity. These network entities may take various forms suchas, for example, one or more radio and/or core network entities. Thus,in various implementations, the network nodes 108 and 110 and mayrepresent functionality such as at least one of: mobility management,network management (e.g., via an operation, administration, management,and provisioning entity), call control, session management, gatewayfunctions, interworking functions, or some other suitable networkfunctionality.

The access terminal 102 includes functionality (represented by manualcell set selector 112) to enable a user of the access terminal tomanually select a wireless cell set. In general, a wireless cell setcomprises a set of one or more cells (e.g., at least one access point)where there is a defined relationship specific to that set. One exampleof a wireless cell set is a CSG (described in more detail below). Forconvenience, the discussion that follows may simply refer to the termCSG, rather than the more general term wireless cell set. It should beappreciated, however, that the described concepts may be applicable toother types of defined sets or groups of wireless cells or other similarentities.

To facilitate wireless network (e.g., PLMN) selection, the accessterminal 102 includes a wireless network selection mode switch 114 thatmay switch to a different mode of wireless network selection in responseto the manual selection of a CSG in a different network. Here, differentmodes of wireless network selection may be defined in various ways. Insome implementations, automatic and manual modes of wireless networkselection may be defined. In some implementations, one mode may bedefined to be used when an access terminal is camping on a macro cellwhile another mode may be defined to be used when the access terminal iscamping on a CSG cell. Other types of modes may be used in otherimplementations. In the example of FIG. 1, the access point 104 maycomprise a cell of a home wireless network (e.g., a home PLMN) for theaccess terminal 102 while the access point 106 may comprise a CSG cellof a visited wireless network (e.g., visited PLMN). If the accessterminal 102 was in an automatic mode of wireless network selectionprior to the manual selection of the CSG, the switch 114 mayautomatically switch to a non-automatic mode (e.g., a manual mode) ofwireless network selection. In this way, the access terminal 102 mayremain camped on the selected CSG even if other higher priority wirelessnetworks are able to serve the access terminal 102.

The access terminal 102 also include a data record 116 (i.e., a datamemory) for storing state information for the network selectionprocedures. For example, a record of a previously used wireless networkselection mode (prior selection mode 118) may be maintained so that theswitch 114 may automatically switch back to the prior mode of wirelessnetwork selection if the access terminal loses (e.g., leaves) thewireless coverage of the selected CSG. Similarly, a record of apreviously used wireless network (prior wireless network 120) may bemaintained so that the access terminal 102 may automatically switch backto the prior wireless network if the access terminal loses (e.g.,leaves) the wireless coverage of the selected CSG.

Sample operations of the system 100 will now be described in more detailin conjunction with the flowchart of FIG. 2. For convenience, theoperations of FIG. 2 (or any other operations discussed or taughtherein) may be described as being performed by specific components. Itshould be appreciated, however, that these operations may be performedby other types of components and may be performed using a differentnumber of components. It also should be appreciated that one or more ofthe operations described herein may not be employed in a givenimplementation.

As represented by block 202, in some implementations, one or more cellssets (e.g., CSGs) may be designated as being preferred for selection foran access terminal. For example, a user may prefer to access a certainCSG if that CSG is available. Accordingly, a record of this preferredCSG may be maintained on the access terminal to facilitate selectingthat CSG in the event the access terminal enters the coverage of thatCSG.

As represented by block 204, at various points in time, an accessterminal may utilize a first mode of wireless network selection (e.g.,an automatic mode or a macro cell specific mode) during idle modeoperation. For example, the access terminal may operate in an automaticmode of wireless network selection whereby the access terminalautomatically selects the best available wireless network on a repeatedbasis (e.g., by operation of a background procedure that search forPLMNs). Such a selection procedure may employ a list that specifies oneor more preferred wireless networks (e.g., a prioritized list that ranksPLMNs in priority order). Thus, whenever the access terminal detects ahigher priority wireless network, the access terminal may automaticallyselect that network. In a typical case, a user's home wireless networkmay be assigned the highest priority (e.g., designated as being thepreferred wireless network), while others wireless networks that theuser is authorized to access may have lower priority.

The access terminal may maintain a record of the current mode ofwireless network selection. As mentioned above, this record may be usedto facilitate efficiently switching back to this mode at some laterpoint in time.

As represented by block 206, at some point in time, a user of the accessterminal may manually select a CSG that is on a different wirelessnetwork. For example, the user may use a user input device of the accessterminal to activate a manual CSG selection mode. A user may wish tomanually select a CSG to, for example, obtain a service uniquelyprovided by the CSG. For example, the CSG may be deployed by a thirdparty (e.g., a retailer) to provide free coverage for customers orprovide coverage on a fee basis.

Upon activation of this mode, the access terminal may then scan foravailable cells advertizing at least one CSG. For example, the accessterminal may monitor for signals from nearby access points and determinewhether any of these access points are broadcasting signals thatindicate that the access point is associated with one or more CSGs.

Upon identifying one or more cells associated with one or more CSGs, theaccess terminal may display a corresponding list on a display device ofthe access terminal. In some aspects, this list may comprise at leastone identifier corresponding to any available cells advertising at leastone CSG. For example, for each CSG that was detected, the list maycomprise one or more of: an identifier of the CSG, an identifier of acell advertising the CSG, or an identifier of the wireless network(e.g., PLMN) of the cell advertising the CSG. In a case where multiplecells are advertising the same CSG, the access terminal may list all ofthese cells or some of these cells (e.g., the cell associated with thehighest received signal strength at the access terminal).

The user may then use a user input device to select one of the itemsfrom the list (e.g., one of the CSGs). Accordingly, the access terminalmay select one of the available cells based on an indication from theuser input device. For example, if there is only one cell advertisingthe CSG selected by the user, the access terminal will select that cell(e.g., select the cell for camping by the access terminal). If there aremultiple cells advertising the CSG selected by the user, the accessterminal may select the cell from that set of cells that provides thehighest received signal strength, the highest quality of service for theaccess terminal, or some other desired attribute. As discussed above, insome cases, a CSG may be designated as preferred for selection. In sucha case, the selection of the cell may be based on this designation.

As represented by block 208, as a result of the manual selection of aCSG on a different wireless network, the access terminal may switch to adifferent mode of wireless network selection (e.g., a manual mode or aCSG cell specific mode). For example, the access terminal may switch toa non-automatic (e.g., manual) mode of wireless network selection. Inthis way, a selection of the wireless network of the CSG cell (thatresults from the manual selection of the CSG) will not be subsequentlyoverridden as could happen if the access terminal remained in theautomatic mode of wireless network selection.

As represented by block 210, in conjunction with the selection of thecell at block 206, the access terminal camps on the selected cell. Insome aspects, camping on a cell may comprise one or more of: receivingpages from the cell, establishing communication with the cell, ordecoding broadcast transmissions from the cell.

As represented by block 212, at some point in time, the access terminalmay determine that it is no longer receiving service from the CSG (e.g.,by determining that the access terminal is no longer camping on any cellof the CSG). Here, service may be lost, for example, due to the accessterminal moving out of the service area of the cell(s) advertising theCSG, the access terminal being subjected to interference that causes aloss in service, or the access terminal losing service for some otherreason.

As represented by block 214, upon determining that the access terminalis no longer receiving service from the CSG, the access terminal mayautomatically (e.g., without requiring action by the user) switch itsmode of wireless network selection. For example, the access terminal mayswitch back to the mode of operation specified by the record maintainedat block 204 (e.g., an automatic mode of PLMN selection). As discussedabove, this may correspond to the mode of operation that was in useimmediately before manual selection of the CSG.

By automatically switching to a prior mode of wireless network selectionin this manner, the access terminal may, for example, avoid staying on awireless network (e.g., a visited PLMN) from which service is notavailable or avoid requiring user intervention to prevent loss ofcoverage. For example, in some cases a wireless network may allow theaccess terminal to access cells of the CSG, but no other cells on thatwireless network. In these cases, upon leaving the coverage of the CSG,the access terminal could fall out of coverage if it had stayed in themanual mode of wireless network selection (e.g., the access terminalwould remain on the selected wireless network). While this issue couldbe addressed by automatically requesting the user to choose anotherwireless network, the teachings herein may be advantageously employed tomaintain coverage without requiring user intervention.

As represented by block 216, the access terminal may be configured toautomatically select a cell of the CSG if the access terminal returns tothe wireless coverage of the CSG within a defined period of time. Forexample, if the access terminal enters wireless coverage of a celladvertising the CSG within a defined period of time after thedetermination of block 212, the access terminal may automatically selectthat cell and commence camping on that cell. Thus, in the event theaccess terminal temporarily loses the CSG service, the service may bereacquired without requiring user intervention.

Sample implementations of the above procedures will now be describedwith reference to FIGS. 3-7. FIGS. 3 and 4 describe sample operationsthat may be performed in conjunction with wireless network selection orthe switching of the selection mode. FIG. 5 describes sample operationsthat may be performed in conjunction with returning to a CSG within adefined period of time. FIG. 6 describes sample operations that may beperformed in conjunction with returning to a prior wireless network.FIG. 7 describes sample functional components that may be used toperform the operations taught herein.

As represented by block 302 of FIG. 3, the access terminal maintains arecord of the current mode of wireless network selection. Thus, duringnormal operation, the record is updated whenever the access terminalswitches its selection mode. As mentioned above, an access terminal mayusually operate in an automatic mode (or a macro cell specific mode) ofwireless network selection.

As represented by block 304, at some point in time the access terminalselects a cell advertising a CSG. These operations may correspond to,for example, the operations described above at block 206.

As represented by block 306, the access terminal identifies the wirelessnetwork associated with the selected cell. For example, the accessterminal may determine which PLMN the selected cell is on. In somecases, the identified network may be considered to be a visited networkfrom the perspective of the access terminal. For example, the selectedcell may be on a wireless network that is different than the currentlyregistered wireless network (i.e., the wireless network at which theaccess terminal is currently registered). Also, if the access terminalis not currently registered on any wireless network, the selected cellmay be on a wireless network that is different from a currentlypreferred wireless network (e.g., the user's home wireless network).

As represented by block 308, the access terminal may switch from thecurrent mode of wireless network selection to a different mode ofwireless network selection as a result of the identification of thewireless network at block 306. As discussed above, the access terminalmay switch to a non-automatic mode (or a CSG cell specific mode) ofwireless network selection if the user selected a CSG on a differentwireless network. For example, the access terminal may switch to amanual selection mode if the identified wireless network (e.g., avisited network) is different that the currently registered wirelessnetwork (e.g., a home network) or the currently preferred wirelessnetwork (e.g., a home network). Upon switching selection modes in thiscase, the access terminal does not record the new selection mode as the“current” selection mode (described at block 302). Rather, as discussedbelow, the “current” selection mode record is left unchanged so that theaccess terminal may later determine the mode that was in use prior tothe selection of the CSG at block 304. As an alternative, the accessterminal may record the new selection mode as the “current” selectionmode and the previous current selection mode as the “last” selectionmode.

Once the access terminal successfully establishes communication with theselected cell, the access terminal may register at the identifiednetwork (block 310) via the selected cell and camp on the cell toreceive pages, data, and broadcast information. In addition, in theevent multiple cells are advertising the CSG, the access terminal mayswitch to a different cell of the CSG (e.g., upon moving to a differentfloor of the retailer providing the CSG service). At some point in time,however, the access terminal may not be able to select any cell of theCSG (e.g., the user may have left the store that provided the CSGservice). Accordingly, as represented by block 312, the access terminalmay determine that it is no longer camping on a cell of the CSG (e.g.,it is not camping on any of the cells advertising the CSG).

As represented by block 314, the access terminal may switch to adifferent mode of wireless network selection as a result of thedetermination of block 312. As mentioned above, the switch may bepredicated on a determination that the access terminal cannot select anycell of the CSG. In addition, in some cases the switch may be predicatedon a determination that the access terminal cannot select any other cellof the identified wireless network (e.g., the wireless network onlyallows the access terminal to access cells of the CSG).

As mentioned above, upon leaving the CSG, the access terminal may switchfrom the manual mode of wireless network selection to the prior modespecified by the record maintained at block 302 (e.g., automatic mode).Upon returning to automatic mode, the access terminal will likelyreselect the wireless network (e.g., a home wireless network) that theaccess terminal was on prior to the manual selection of the CSG.

The operations of FIG. 3 may be implemented in various ways. FIG. 4illustrates sample non-access stratum (NAS) and access stratum (AS)procedures that may be employed to achieve PLMN selection modeswitching.

At step 1, the user requests CSG manual selection which triggers the NASin the access terminal to request a list of available CSG cells acrossall PLMNs. Here, manual selection may apply to CSG cells both in and outof the access terminal's allowed CSG list (e.g., whitelist) and anyoperator CSG list.

At step 2, in response to the NAS request, the AS scans all radiofrequency (RF) channels according to its capabilities and returns a listof available CSG cells for a user to select from across all PLMNs. Forexample, the access terminal may scan the UTRA and/or E-UTRA bandsaccording to its capabilities to find available CSG identifiers (IDs).

On each carrier, the AS may search (at least) for the strongest cell,read its system information and report available CSG ID(s) belonging tothe registered PLMN together with their Home NodeB (HNB) name, ifavailable, to the NAS for a user to select from. The search foravailable CSG IDs may be stopped on request of the NAS.

At step 3, the access terminal displays to the user all the CSGs thatare available and the associated PLMNs. The access terminal also mayindicate the text-based HNB name if available. The available CSG IDs maybe displayed, for example, in the following order: 1) The CSG IDs thatare contained in the allowed CSG list; 2) The CSG IDs that are containedin the operator CSG list; 3) Any other CSG ID not included in theallowed CSG list or the operator CSG list.

When there are multiple cells with the same CSG ID on the same PLMN,only the HNB name of the strongest cell for that CSG ID is displayed insome implementations. The access terminal may also display otherinformation such as the signal strength of the CSG cell and whether theCSG cell belongs to the current PLMN. For example, an access terminalmay use signal strength bars to indicate that it has detected thepresence of the CSG cell. However, the access terminal may decide to notselect that cell due to unsuitable RF conditions. The access terminalwill generally not display a PLMN for which there is no CSG cellavailable for selection.

At step 4, the NAS requests the AS to camp on the manually selected(PLMN, CSG) pair.

At step 5, the AS performs the reselection procedures required to campon the best cell in that PLMN for that CSG by searching for anacceptable or suitable cell belonging to the selected CSG ID.

At step 6, the AS returns an indication that camping on the CSG cell wassuccessful, including details of the CSG cell such as the CSG ID,tracking area code, location area code, and routing area code.

At step 7, if the user selects a CSG cell within the same PLMN it iscurrently camped on, and the CSG cell has a CSG ID not in the accessterminal's allowed CSG list, the access terminal may perform a locationregistration procedure (e.g., location area update, routing area update,tracking area update). If the location registration procedure issuccessful, the access terminal may add the CSG to the allowed CSG list.

If the user selects a CSG cell in a PLMN that is different from theregistered PLMN (RPLMN), then the following applies: 1) The accessterminal stores a duplicate of the RPLMN and a duplicate of the currentPLMN selection mode; 2) The access terminal enters into a manual mode ofPLMN selection; 3) The access terminal selects the PLMN corresponding tothe CSG and attempts to register on the selected CSG cell in the PLMN;4) If the registration fails, the access terminal returns to the storedduplicate PLMN selection mode and uses the stored duplicate value ofRPLMN and initiates the procedures to reselect to a cell on theappropriate PLMN including registering on the PLMN.

If the registration attempt is accepted, the access terminal may add theCSG identity to the allowed CSG list, unless the cell is a hybrid cellor the identity is already present in the list.

At step 8, the access terminal loses coverage of the CSG or other RFconditions cause the access terminal to move out of coverage of cell(s)belonging to the selected CSG.

At step 9, the AS informs the NAS that a CSG cell with the same CSG IDis no longer available for reselection.

At step 10, if the user selects a CSG cell in a PLMN that is differentfrom the RPLMN and the access terminal is no longer in the coverage ofthe CSG, the access terminal returns to the stored duplicate PLMNselection mode and uses the stored duplicate value of RPLMN andinitiates procedures to reselect to a cell on the appropriate PLMN,including registering on the PLMN.

Referring now to FIG. 5, in some implementations, an access terminal maybe configured to automatically reselect the CSG if it returns to the CSGwithin a defined period of time. As represented by blocks 502 and 504,an access terminal may select a cell of a CSG for camping, switch themode of wireless network selection (e.g., to manual mode), camp on thecell, and then at some later point in time cease camping on the cell.Thus, the operations of blocks 502 and 504 may correspond, for example,to the operations described above at blocks 202-212 and/or blocks302-312.

As represented by block 506, the access terminal may switch to anothermode of wireless network selection (e.g., to the automatic mode or themacro cell specific mode) as a result of the determination that theaccess terminal is no longer camped on a cell of the CSG. Theseoperations may thus correspond, for example, to the operations describedabove at blocks 214 and/or 314.

As represented by block 508, the access terminal may or may not acquireother service upon leaving the CSG. In some cases, upon cessation ofcamping on any cell of the CSG and switching the mode of wirelessnetwork selection, the access terminal will detect and select a wirelessnetwork (e.g., a home wireless network) that is different from thewireless network of the cell selected at block 502.

As represented by block 510, the access terminal may keep track ofwhether it has returned to the coverage of the CSG within a definedperiod of time after leaving the coverage. For example, a timer may bestarted once it is determined that the access terminal has ceasedcamping on any cell of the CSG. The access terminal may then commencemonitoring to determine whether it returns to the wireless coverage of acell of the CSG before the timer expires (i.e., within the definedperiod of time)

As represented by block 512, if it is determined that the accessterminal has returned to the wireless coverage of a cell of the CSGwithin the defined period of time, the access terminal may select thatcell of the CSG for establishing communication. In some aspects, theselection of the cell for establishing communication may comprise, forexample, accessing the cell and/or camping on the cell (e.g., to receiveone or more of: pages, data, or broadcast information from the cell).

In conjunction with this selection of the cell, the access terminal mayalso reselect the wireless network of the cell and switch to a differentmode of wireless network selection (e.g., return to the manual mode orthe CSG cell specific mode). Advantageously, the selection of the celland the wireless network and the mode switch may be performedautomatically, without intervention of the user (e.g., without requiringthe user to perform a manual selection).

Referring now to FIG. 6, in some implementations, an access terminal maybe configured to automatically return to a prior wireless network. Asrepresented by block 602, at some point in time an access terminal mayoperate in a mode of wireless network selection that enables a specificwireless network to be selected. For example, the access terminal maysupport a manual mode of wireless network selection whereby a user mayselect a wireless network from a set of wireless networks that weredetected by the access terminal (e.g., and presented to the user via alist displayed on a display screen).

As represented by block 604, the access terminal maintains a record ofthe currently selected wireless network. This wireless network maycomprise, for example, a home wireless network, a visited wirelessnetwork, or some other type of wireless network.

As represented by blocks 606 and 608, at some point in time the accessterminal may select a cell advertising a CSG and identify the wirelessnetwork (e.g., a visited wireless network) associated with the selectedcell. Accordingly, the operations of blocks 606 and 608 may correspondto, for example, the operations described above at blocks 304-308.

As represented by block 610, in some cases the access terminal mayregister at the identified wireless network. For example, registrationmay be performed if the identified wireless network is different thanthe wireless network discussed at block 604 (the “current” wirelessnetwork), if the identified wireless network is different than acurrently preferred wireless network, or if the access terminal is notregistered at any network.

As represented by block 612, at some point in time, the access terminalmay leave the coverage of the CSG. For example, as discussed above atblock 212 and/or 312, it may be determined that the access terminal isno longer camping on any cell of the CSG.

As represented by block 614, the access terminal may then return to thewireless network identified by the record maintained as described aboveat block 604. For example, upon determining that a manual mode ofwireless network selection was employed immediately prior to selectingthe cell at block 606 (e.g., by referencing the maintained record of theselection mode as discussed herein), the access terminal may select thewireless network (e.g., the home wireless network) that was manuallyselected by the user while in that mode. Advantageously, the selectionof the wireless network may be performed automatically, withoutintervention of the user (e.g., without requiring the user to performanother manual selection).

The coverage re-entry operations described above at FIG. 5 also may beemployed in conjunction with the operations of FIG. 6. For example, ifthe access terminal returns to the coverage of the CSG within a definedperiod of time after leaving coverage at block 612, the access terminalmay automatically select a cell of the CSG as discussed above.

FIG. 7 illustrates several sample components that may be incorporatedinto a node such as an access terminal 700 (e.g., corresponding to theaccess terminal 102) to perform mode switch and network selection astaught herein. The described components also may be incorporated intoother nodes in a communication system. For example, other nodes in asystem may include components similar to those described for the accessterminal 700 to provide similar functionality. A given node may containone or more of the described components. For example, an access terminalmay contain multiple transceiver components that enable the accessterminal to operate on multiple frequencies and/or communicate viadifferent technologies.

As shown in FIG. 7, the access terminal 700 includes a transceiver 702for communicating with other nodes. The transceiver 702 includes atransmitter 704 for sending signals (e.g., to an access point) and areceiver 706 for receiving signals (e.g., scanning for signals from anaccess point).

The access terminal 700 also includes other components that may be usedin conjunction with mode switch and network selection operations astaught herein. For example, the access terminal 700 may include acommunication controller 708 for managing communication with other nodesand for providing other related functionality as taught herein. In someaspects, the communication controller may be used to send messages andprocess received messages for selecting a cell (e.g., receive messagesincluding CSG identifiers, wireless network identifiers, etc.),identifying a wireless network associated with a cell of a CSG,registering with a network, determining whether the access terminal iscamping on a cell of CSG, and determining whether the access terminalhas returned to wireless coverage of a cell of a CSG (e.g., within adefined period of time).

In addition, the access terminal 700 may include a network selector 710(e.g., corresponding to mode switch 114) for performing mode switchesand network selection operations and for providing other relatedfunctionality as taught herein. For example, the network selector 710may switch modes based on the identification of a wireless networkand/or based on a determination that an access terminal is no longercamped on a cell of a CSG, maintain a record of the current mode ofwireless network selection, return to a mode identified by the record,select a wireless network based on a determination that an accessterminal is no longer camped on a cell of a CSG, designate that a closedCSG is preferred for selection, and return to a wireless networkidentified by a maintained record if an access terminal leaves wirelesscoverage of a cell of a CSG.

The access terminal 700 also may include a cell selector 712 (e.g.,corresponding to selector 112) for selecting cells and for providingother related functionality as taught herein. For example, the cellselector may select a cell advertising a CSG, and select a cell of a CSGif an access terminal enters wireless coverage of the cell within adefined period of time after the access terminal ceased camping on anycell of the CSG.

The access terminal 700 also may include input and output devices forinterfacing with a user. For example, the access point may include adisplay device 714 and a user input device 716.

The teaching herein may be realized in various ways in differentimplementations. Two sample implementations are described below in thecontext of manual selection of a CSG that is on a different PLMN fromthe PLMN that is currently serving an access terminal.

In the first implementation, the non-automatic mode of wireless networkselection described above is referred to as a CSG-triggered mode ofoperation. In some aspects, the CSG-triggered mode of operation maycomprise a manual mode of operation where state information (e.g.,indicative of the prior selection mode and/or wireless network) ismaintained to facilitate the desired wireless network selectionbehavior. For example, once a user manually selects a CSG on a differentPLMN and the access terminal selects this PLMN, the access terminal maybe considered to be in a CSG-triggered mode (e.g., a form of a manualmode of PLMN selection).

In this mode, the access terminal remains camped in the new PLMN untilconditions trigger another behavior. For example, when the accessstratum (AS) loses coverage on the new PLMN, selection may be triggeredas usual. However, at the time of this trigger, the non-access stratum(NAS) behaves as if the previous mode of PLMN selection had beenautomatic. In most cases, the access terminal will return to theoriginal serving PLMN, but in any event it may select a new PLMN withoutuser intervention.

In some cases, the manual CSG selection may cause specific AS behaviorsto be triggered as a result of the request to camp on the selected CSGcell. For example, this may trigger preferential camping on therequested cell.

The AS may maintain state information in conjunction with the selectionoperations taught herein. For example, the access terminal may maintaina record indicating that the access terminal triggered PLMN selectionfor the benefit of the specific serving CSG.

In the example just described, the trigger for PLMN selection was theloss of coverage from the PLMN selected in the CSG-triggered procedure.However, other triggers could be employed in the AS (e.g., to stimulateor inhibit triggering of PLMN selection in response to various eventsspecific to the CSG environment).

As one example, the AS could consider the target CSG cell to be special,and could trigger PLMN selection at the next cell reselection. Thisoperational flow may be identical to that described above, with theexception that cell reselection is used as the trigger rather than lossof coverage.

A more sophisticated version of this modification, which may be usefulin campus CSG deployments, is for the AS to trigger PLMN selection onlyupon reselection to a cell not associated with the same CSG. That is,the AS filters reselection events and triggers (automatic) PLMNselection only if it is being forced to leave the user's chosen CSG.

These modifications may create a user-experience problem if the userrepeatedly leaves the target cell (or CSG) for a brief period, thenreturns. This could occur either because of radio conditions or useractivity (e.g., going from a store that provides the CSG service to acar parked outside and back). In such situations, the above operationsmay occur repeatedly, meaning that the user may be “dumped” onto normalmacro cell coverage and forced to repeat manual CSG selection afterreturning to the coverage of the CSG cell. In practice, this scenariomay be obtrusive for the user. Moreover, depending on the interactionbetween the PLMNs, this scenario may be disruptive to services, resultin repeated billing, or present other problems. Therefore, as discussedabove, it may be desirable for either the NAS or the AS to maintain asupervisory timer when the PLMN selection state is set to CSG-triggered,so that a physical departure from the CSG (e.g., resulting from loss ofcoverage from the new PLMN, cell reselection, etc.—whatever triggers theAS to request PLMN selection) does not cause PLMN selection until thetimer expires.

In some cases, the access terminal may be out of coverage while thesupervisory timer is running (depending on the nature of the AStriggering condition). Thus, the length of the timer may be tuned to avalue appropriate to the deployment scenario. In some cases the timermay be operator-configurable. For example, the timer could configurableon a per-cell basis. Here, the configuration may be delivered as part ofthe system information, either on the CSG (which may “know” the mostabout its deployment environment) or on the neighboring macro cells ofvarious PLMNs (which may have the strongest interest in ensuring a gooduser experience in interoperation with the CSG). In other cases,however, the timer may be a fixed value in the specification, a userconfiguration option, or defined in some other way.

In the second implementation, if a user manually selects a CSG cell in aPLMN that is different from the current camped PLMN, the access pointmay be configured to provide the behavior that follows. In some aspects,provisions are made to determine a period of time during which theaccess terminal shall prefer to camp on the manually selected CSG cellbased on reselection procedures. If the access terminal is in coverageof the CSG on the selected PLMN it will stay there until either: 1) Itssubscription to the CSG or the period of time expires; or 2) The usermanually selects to another CSG cell or PLMN. If the access terminalmoves out of the coverage of the CSG on the selected PLMN it will goback to its previous state where: 1) If it was in manual mode it will goto the last PLMN selected before this PLMN; and 2) If it was inautomatic mode it will revert to normal automatic selection. If theaccess terminal moves into coverage of the CSG on the new PLMN, then: 1)If it is before the period of time expires the access terminal willselect that CSG cell even if it is on another PLMN with higher priority,i.e., ignore PLMN selection mode; and 2) If it is after the timerexpires then the PLMN selection mode will take precedence in accessterminal reselection.

As discussed above, in some aspects the teachings herein may be employedin an environment that includes macro scale coverage (e.g., a large areacellular network such as a 3G network, typically referred to as a macrocell network or a WAN) and smaller scale coverage (e.g., aresidence-based or building-based network environment, typicallyreferred to as a LAN). As an access terminal (AT) moves through such anenvironment, the access terminal may be served in certain locations byaccess points that provide macro coverage while the access terminal maybe served at other locations by access points that provide smaller scalecoverage. In some aspects, the smaller coverage nodes may be used toprovide incremental capacity growth, in-building coverage, and differentservices (e.g., for a more robust user experience).

A node (e.g., an access point) that provides coverage over a relativelylarge area may be referred to as a macro node while a node that providescoverage over a relatively small area (e.g., a residence) may bereferred to as a femto node. It should be appreciated that the teachingsherein may be applicable to nodes associated with other types ofcoverage areas. For example, a pico node may provide coverage (e.g.,coverage within a commercial building) over an area that is smaller thana macro area and larger than a femto area. In various applications,other terminology may be used to reference a macro node, a femto node,or other access point-type nodes. For example, a macro node may beconfigured or referred to as an access node, base station, access point,eNodeB, macro cell, and so on. Also, a femto node may be configured orreferred to as a Home NodeB, Home eNodeB, access point base station,femto cell, and so on. In some implementations, a node may be associatedwith (e.g., divided into) one or more cells or sectors. A cell or sectorassociated with a macro node, a femto node, or a pico node may bereferred to as a macro cell, a femto cell, or a pico cell, respectively.

FIG. 8 illustrates a wireless communication system 800, configured tosupport a number of users, in which the teachings herein may beimplemented. The system 800 provides communication for multiple cells802, such as, for example, macro cells 802A-802G, with each cell beingserviced by a corresponding access point 804 (e.g., access points804A-804G). As shown in FIG. 8, access terminals 806 (e.g., accessterminals 806A-806L) may be dispersed at various locations throughoutthe system over time. Each access terminal 806 may communicate with oneor more access points 804 on a forward link (FL) and/or a reverse link(RL) at a given moment, depending upon whether the access terminal 806is active and whether it is in soft handoff, for example. The wirelesscommunication system 800 may provide service over a large geographicregion. For example, macro cells 802A-802G may cover a few blocks in aneighborhood or several miles in rural environment.

FIG. 9 illustrates an exemplary communication system 900 where one ormore femto nodes are deployed within a network environment.Specifically, the system 900 includes multiple femto nodes 910 (e.g.,femto nodes 910A and 910B) installed in a relatively small scale networkenvironment (e.g., in one or more user residences 930). Each femto node910 may be coupled to a wide area network 940 (e.g., the Internet) and amobile operator core network 950 via a DSL router, a cable modem, awireless link, or other connectivity means (not shown). As will bediscussed below, each femto node 910 may be configured to serveassociated access terminals 920 (e.g., access terminal 920A) and,optionally, other (e.g., hybrid or alien) access terminals 920 (e.g.,access terminal 920B). In other words, access to femto nodes 910 may berestricted whereby a given access terminal 920 may be served by a set ofdesignated (e.g., home) femto node(s) 910 but may not be served by anynon-designated femto nodes 910 (e.g., a neighbor's femto node 910).

FIG. 10 illustrates an example of a coverage map 1000 where severaltracking areas 1002 (or routing areas or location areas) are defined,each of which includes several macro coverage areas 1004. Here, areas ofcoverage associated with tracking areas 1002A, 1002B, and 1002C aredelineated by the wide lines and the macro coverage areas 1004 arerepresented by the larger hexagons. The tracking areas 1002 also includefemto coverage areas 1006. In this example, each of the femto coverageareas 1006 (e.g., femto coverage areas 1006B and 1006C) is depictedwithin one or more macro coverage areas 1004 (e.g., macro coverage areas1004A and 1004B). It should be appreciated, however, that some or all ofa femto coverage area 1006 may not lie within a macro coverage area1004. In practice, a large number of femto coverage areas 1006 (e.g.,femto coverage areas 1006A and 1006D) may be defined within a giventracking area 1002 or macro coverage area 1004. Also, one or more picocoverage areas (not shown) may be defined within a given tracking area1002 or macro coverage area 1004.

Referring again to FIG. 9, the owner of a femto node 910 may subscribeto mobile service, such as, for example, 3G mobile service, offeredthrough the mobile operator core network 950. In addition, an accessterminal 920 may be capable of operating both in macro environments andin smaller scale (e.g., residential) network environments. In otherwords, depending on the current location of the access terminal 920, theaccess terminal 920 may be served by a macro cell access point 960associated with the mobile operator core network 950 or by any one of aset of femto nodes 910 (e.g., the femto nodes 910A and 910B that residewithin a corresponding user residence 930). For example, when asubscriber is outside his home, he is served by a standard macro accesspoint (e.g., access node 960) and when the subscriber is at home, he isserved by a femto node (e.g., node 910A). Here, a femto node 910 may bebackward compatible with legacy access terminals 920.

A femto node 910 may be deployed on a single frequency or, in thealternative, on multiple frequencies. Depending on the particularconfiguration, the single frequency or one or more of the multiplefrequencies may overlap with one or more frequencies used by a macroaccess point (e.g., access point 960).

In some aspects, an access terminal 920 may be configured to connect toa preferred femto node (e.g., the home femto node of the access terminal920) whenever such connectivity is possible. For example, whenever theaccess terminal 920A is within the user's residence 930, it may bedesired that the access terminal 920A communicate only with the homefemto node 910A or 910B.

In some aspects, if the access terminal 920 operates within the macrocellular network 950 but is not residing on its most preferred network(e.g., as defined in a preferred roaming list), the access terminal 920may continue to search for the most preferred network (e.g., thepreferred femto node 910) using a better system reselection (BSR), whichmay involve a periodic scanning of available systems to determinewhether better systems are currently available, and subsequent effortsto associate with such preferred systems. With the acquisition entry,the access terminal 920 may limit the search for specific band andchannel. For example, one or more femto channels may be defined wherebyall femto nodes (or all restricted femto nodes) in a region operate onthe femto channel(s). The search for the most preferred system may berepeated periodically. Upon discovery of a preferred femto node 910, theaccess terminal 920 selects the femto node 910 for camping within itscoverage area.

A femto node may be restricted in some aspects. For example, a givenfemto node may only provide certain services to certain accessterminals. In deployments with so-called restricted (or closed)association, a given access terminal may only be served by the macrocell mobile network and a defined set of femto nodes (e.g., the femtonodes 910 that reside within the corresponding user residence 930). Insome implementations, a node may be restricted to not provide, for atleast one node, at least one of: signaling, data access, registration,paging, or service.

In some aspects, a restricted femto node (which may also be referred toas a closed subscriber group Home NodeB) is one that provides service toa restricted provisioned set of access terminals. This set may betemporarily or permanently extended as necessary. In some aspects, aclosed subscriber group identifies subscribers of an operator who arepermitted to access one or more cells of a wireless network (e.g., PLMN)but which have restricted access. In some aspects, a closed subscribergroup may be defined as the set of access points (e.g., femto nodes)that share a common access control list of access terminals.

Various relationships may thus exist between a given femto node and agiven access terminal. For example, from the perspective of an accessterminal, an open femto node may refer to a femto node with norestricted association (e.g., the femto node allows access to any accessterminal). A restricted femto node may refer to a femto node that isrestricted in some manner (e.g., restricted for association and/orregistration). A home femto node may refer to a femto node on which theaccess terminal is authorized to access and operate on (e.g., permanentaccess is provided for a defined set of one or more access terminals). Ahybrid (or guest) femto node may refer to a femto node on which anaccess terminal is temporarily authorized to access or operate on. Analien femto node may refer to a femto node on which the access terminalis not authorized to access or operate on, except for perhaps emergencysituations (e.g., 911 calls).

From a restricted femto node perspective, a home access terminal mayrefer to an access terminal that is authorized to access the restrictedfemto node (e.g., the access terminal has permanent access to the femtonode). A guest access terminal may refer to an access terminal withtemporary access to the restricted femto node (e.g., limited based ondeadline, time of use, bytes, connection count, or some other criterionor criteria). An alien access terminal may refer to an access terminalthat does not have permission to access the restricted femto node,except for perhaps emergency situations, for example, such as 911 calls(e.g., an access terminal that does not have the credentials orpermission to register with the restricted femto node).

For convenience, the disclosure herein describes various functionalityin the context of a femto node. It should be appreciated, however, thata pico node may provide the same or similar functionality for a largercoverage area. For example, a pico node may be restricted, a home piconode may be defined for a given access terminal, and so on.

The teachings herein may be employed in a wireless multiple-accesscommunication system that simultaneously supports communication formultiple wireless access terminals. Here, each terminal may communicatewith one or more access points via transmissions on the forward andreverse links. The forward link (or downlink) refers to thecommunication link from the access points to the terminals, and thereverse link (or uplink) refers to the communication link from theterminals to the access points. This communication link may beestablished via a single-in-single-out system, amultiple-in-multiple-out (MIMO) system, or some other type of system.

A MIMO system employs multiple (N_(T)) transmit antennas and multiple(N_(R)) receive antennas for data transmission. A MIMO channel formed bythe N_(T) transmit and N_(R) receive antennas may be decomposed intoN_(S) independent channels, which are also referred to as spatialchannels, where N_(S)≦min {N_(T), N_(R)}. Each of the N_(S) independentchannels corresponds to a dimension. The MIMO system may provideimproved performance (e.g., higher throughput and/or greaterreliability) if the additional dimensionalities created by the multipletransmit and receive antennas are utilized.

A MIMO system may support time division duplex (TDD) and frequencydivision duplex (FDD). In a TDD system, the forward and reverse linktransmissions are on the same frequency region so that the reciprocityprinciple allows the estimation of the forward link channel from thereverse link channel. This enables the access point to extract transmitbeam-forming gain on the forward link when multiple antennas areavailable at the access point.

FIG. 11 illustrates a wireless device 1110 (e.g., an access point) and awireless device 1150 (e.g., an access terminal) of a sample MIMO system1100. At the device 1110, traffic data for a number of data streams isprovided from a data source 1112 to a transmit (TX) data processor 1114.Each data stream may then be transmitted over a respective transmitantenna.

The TX data processor 1114 formats, codes, and interleaves the trafficdata for each data stream based on a particular coding scheme selectedfor that data stream to provide coded data. The coded data for each datastream may be multiplexed with pilot data using OFDM techniques. Thepilot data is typically a known data pattern that is processed in aknown manner and may be used at the receiver system to estimate thechannel response. The multiplexed pilot and coded data for each datastream is then modulated (i.e., symbol mapped) based on a particularmodulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM) selected for thatdata stream to provide modulation symbols. The data rate, coding, andmodulation for each data stream may be determined by instructionsperformed by a processor 1130. A data memory 1132 may store programcode, data, and other information used by the processor 1130 or othercomponents of the device 1110.

The modulation symbols for all data streams are then provided to a TXMIMO processor 1120, which may further process the modulation symbols(e.g., for OFDM). The TX MIMO processor 1120 then provides N_(T)modulation symbol streams to N_(T) transceivers (XCVR) 1122A through1122T. In some aspects, the TX MIMO processor 1120 applies beam-formingweights to the symbols of the data streams and to the antenna from whichthe symbol is being transmitted.

Each transceiver 1122 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel. N_(T)modulated signals from transceivers 1122A through 1122T are thentransmitted from N_(T) antennas 1124A through 1124T, respectively.

At the device 1150, the transmitted modulated signals are received byN_(R) antennas 1152A through 1152R and the received signal from eachantenna 1152 is provided to a respective transceiver (XCVR) 1154Athrough 1154R. Each transceiver 1154 conditions (e.g., filters,amplifies, and downconverts) a respective received signal, digitizes theconditioned signal to provide samples, and further processes the samplesto provide a corresponding “received” symbol stream.

A receive (RX) data processor 1160 then receives and processes the N_(R)received symbol streams from N_(R) transceivers 1154 based on aparticular receiver processing technique to provide N_(T) “detected”symbol streams. The RX data processor 1160 then demodulates,deinterleaves, and decodes each detected symbol stream to recover thetraffic data for the data stream. The processing by the RX dataprocessor 1160 is complementary to that performed by the TX MIMOprocessor 1120 and the TX data processor 1114 at the device 1110.

A processor 1170 periodically determines which pre-coding matrix to use(discussed below). The processor 1170 formulates a reverse link messagecomprising a matrix index portion and a rank value portion. A datamemory 1172 may store program code, data, and other information used bythe processor 1170 or other components of the device 1150.

The reverse link message may comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message is then processed by a TX data processor 1138,which also receives traffic data for a number of data streams from adata source 1136, modulated by a modulator 1180, conditioned by thetransceivers 1154A through 1154R, and transmitted back to the device1110.

At the device 1110, the modulated signals from the device 1150 arereceived by the antennas 1124, conditioned by the transceivers 1122,demodulated by a demodulator (DEMOD) 1140, and processed by a RX dataprocessor 1142 to extract the reverse link message transmitted by thedevice 1150. The processor 1130 then determines which pre-coding matrixto use for determining the beam-forming weights then processes theextracted message.

FIG. 11 also illustrates that the communication components may includeone or more components that perform network control operations as taughtherein. For example, a network control component 1192 may cooperate withthe processor 1170 and/or other components of the device 1150 to selectnetwork selection modes and wireless networks as taught herein. Itshould be appreciated that for each device 1110 and 1150 thefunctionality of two or more of the described components may be providedby a single component. For example, a single processing component mayprovide the functionality of the network control component 1192 and theprocessor 1170.

The teachings herein may be incorporated into various types ofcommunication systems and/or system components. In some aspects, theteachings herein may be employed in a multiple-access system capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., by specifying one or more of bandwidth, transmitpower, coding, interleaving, and so on). For example, the teachingsherein may be applied to any one or combinations of the followingtechnologies: Code Division Multiple Access (CDMA) systems,Multiple-Carrier CDMA (MCCDMA), Wideband CDMA (W-CDMA), High-SpeedPacket Access (HSPA, HSPA+) systems, Time Division Multiple Access(TDMA) systems, Frequency Division Multiple Access (FDMA) systems,Single-Carrier FDMA (SC-FDMA) systems, Orthogonal Frequency DivisionMultiple Access (OFDMA) systems, or other multiple access techniques. Awireless communication system employing the teachings herein may bedesigned to implement one or more standards, such as IS-95, cdma2000,IS-856, W-CDMA, TDSCDMA, and other standards. A CDMA network mayimplement a radio technology such as Universal Terrestrial Radio Access(UTRA), cdma2000, or some other technology. UTRA includes W-CDMA and LowChip Rate (LCR). The cdma2000 technology covers IS-2000, IS-95 andIS-856 standards. A TDMA network may implement a radio technology suchas Global System for Mobile Communications (GSM). An OFDMA network mayimplement a radio technology such as Evolved UTRA (E-UTRA), IEEE 802.11,IEEE 802.16, IEEE 802.20, Flash-OFDM®, etc. UTRA, E-UTRA, and GSM arepart of Universal Mobile Telecommunication System (UMTS). The teachingsherein may be implemented in a 3GPP Long Term Evolution (LTE) system, anUltra-Mobile Broadband (UMB) system, and other types of systems. LTE isa release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE aredescribed in documents from an organization named “3rd GenerationPartnership Project” (3GPP), while cdma2000 is described in documentsfrom an organization named “3rd Generation Partnership Project 2”(3GPP2). Although certain aspects of the disclosure may be describedusing 3GPP terminology, it is to be understood that the teachings hereinmay be applied to 3GPP (e.g., Rel99, Rel5, Rel6, Rel7) technology, aswell as 3GPP2 (e.g., 1×RTT, 1×EV-DO RelO, RevA, RevB) technology andother technologies.

The teachings herein may be incorporated into (e.g., implemented withinor performed by) a variety of apparatuses (e.g., nodes). In someaspects, a node (e.g., a wireless node) implemented in accordance withthe teachings herein may comprise an access point or an access terminal.

For example, an access terminal may comprise, be implemented as, orknown as user equipment, a subscriber station, a subscriber unit, amobile station, a mobile, a mobile node, a remote station, a remoteterminal, a user terminal, a user agent, a user device, or some otherterminology. In some implementations an access terminal may comprise acellular telephone, a cordless telephone, a session initiation protocol(SIP) phone, a wireless local loop (WLL) station, a personal digitalassistant (PDA), a handheld device having wireless connectioncapability, or some other suitable processing device connected to awireless modem. Accordingly, one or more aspects taught herein may beincorporated into a phone (e.g., a cellular phone or smart phone), acomputer (e.g., a laptop), a portable communication device, a portablecomputing device (e.g., a personal data assistant), an entertainmentdevice (e.g., a music device, a video device, or a satellite radio), aglobal positioning system device, or any other suitable device that isconfigured to communicate via a wireless medium.

An access point may comprise, be implemented as, or known as a NodeB, aneNodeB, a radio network controller (RNC), a base station (BS), a radiobase station (RBS), a base station controller (BSC), a base transceiverstation (BTS), a transceiver function (TF), a radio transceiver, a radiorouter, a basic service set (BSS), an extended service set (ESS), amacro cell, a macro node, a Home eNB (HeNB), a femto cell, a femto node,a pico node, or some other similar terminology.

In some aspects a node (e.g., an access point) may comprise an accessnode for a communication system. Such an access node may provide, forexample, connectivity for or to a network (e.g., a wide area networksuch as the Internet or a cellular network) via a wired or wirelesscommunication link to the network. Accordingly, an access node mayenable another node (e.g., an access terminal) to access a network orsome other functionality. In addition, it should be appreciated that oneor both of the nodes may be portable or, in some cases, relativelynon-portable.

Also, it should be appreciated that a wireless node may be capable oftransmitting and/or receiving information in a non-wireless manner(e.g., via a wired connection). Thus, a receiver and a transmitter asdiscussed herein may include appropriate communication interfacecomponents (e.g., electrical or optical interface components) tocommunicate via a non-wireless medium.

A wireless node may communicate via one or more wireless communicationlinks that are based on or otherwise support any suitable wirelesscommunication technology. For example, in some aspects a wireless nodemay associate with a network. In some aspects the network may comprise alocal area network or a wide area network. A wireless device may supportor otherwise use one or more of a variety of wireless communicationtechnologies, protocols, or standards such as those discussed herein(e.g., CDMA, TDMA, OFDM, OFDMA, WiMAX, Wi-Fi, and so on). Similarly, awireless node may support or otherwise use one or more of a variety ofcorresponding modulation or multiplexing schemes. A wireless node maythus include appropriate components (e.g., air interfaces) to establishand communicate via one or more wireless communication links using theabove or other wireless communication technologies. For example, awireless node may comprise a wireless transceiver with associatedtransmitter and receiver components that may include various components(e.g., signal generators and signal processors) that facilitatecommunication over a wireless medium.

The functionality described herein (e.g., with regard to one or more ofthe accompanying figures) may correspond in some aspects to similarlydesignated “means for” functionality in the appended claims. Referringto FIGS. 12, 13, 14, and 15, apparatuses 1200, 1300, 1400, and 1500 arerepresented as a series of interrelated functional modules. Here, a cellselecting module 1202, 1308, or 1402 may correspond at least in someaspects to, for example, a cell selector as discussed herein. A wirelessnetwork identifying module 1204 or 1506 may correspond at least in someaspects to, for example, a network selector as discussed herein. Awireless network selection mode switching module 1206 or 1304 maycorrespond at least in some aspects to, for example, a network selectoras discussed herein. A wireless network registering module 1208 or 1508may correspond at least in some aspects to, for example, a communicationcontroller as discussed herein. A camping determining module 1210, 1302,or 1404 may correspond at least in some aspects to, for example, acommunication controller as discussed herein. A record maintainingmodule 1212, 1306, or 1502 may correspond at least in some aspects to,for example, a network selector as discussed herein. A wireless coveragedetermining module 1406 may correspond at least in some aspects to, forexample, a communication controller as discussed herein. A wirelessnetwork selecting module 1408 may correspond at least in some aspectsto, for example, a network selector as discussed herein. A CSGdesignating module 1410 may correspond at least in some aspects to, forexample, a network selector as discussed herein. A cell selecting module1504 may correspond at least in some aspects to, for example, a cellselector as discussed herein. A wireless network returning module 1510may correspond at least in some aspects to, for example, a networkselector as discussed herein.

The functionality of the modules of FIGS. 12-15 may be implemented invarious ways consistent with the teachings herein. In some aspects thefunctionality of these modules may be implemented as one or moreelectrical components. In some aspects the functionality of these blocksmay be implemented as a processing system including one or moreprocessor components. In some aspects the functionality of these modulesmay be implemented using, for example, at least a portion of one or moreintegrated circuits (e.g., an ASIC). As discussed herein, an integratedcircuit may include a processor, software, other related components, orsome combination thereof. The functionality of these modules also may beimplemented in some other manner as taught herein. In some aspects oneor more of any dashed blocks in FIGS. 12-15 are optional.

It should be understood that any reference to an element herein using adesignation such as “first,” “second,” and so forth does not generallylimit the quantity or order of those elements. Rather, thesedesignations may be used herein as a convenient method of distinguishingbetween two or more elements or instances of an element. Thus, areference to first and second elements does not mean that only twoelements may be employed there or that the first element must precedethe second element in some manner. Also, unless stated otherwise a setof elements may comprise one or more elements. In addition, terminologyof the form “at least one of: A, B, or C” used in the description or theclaims means “A or B or C or any combination of these elements.”

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that any of the variousillustrative logical blocks, modules, processors, means, circuits, andalgorithm steps described in connection with the aspects disclosedherein may be implemented as electronic hardware (e.g., a digitalimplementation, an analog implementation, or a combination of the two,which may be designed using source coding or some other technique),various forms of program or design code incorporating instructions(which may be referred to herein, for convenience, as “software” or a“software module”), or combinations of both. To clearly illustrate thisinterchangeability of hardware and software, various illustrativecomponents, blocks, modules, circuits, and steps have been describedabove generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implementedwithin or performed by an integrated circuit (IC), an access terminal,or an access point. The IC may comprise a general purpose processor, adigital signal processor (DSP), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, electrical components, optical components,mechanical components, or any combination thereof designed to performthe functions described herein, and may execute codes or instructionsthat reside within the IC, outside of the IC, or both. A general purposeprocessor may be a microprocessor, but in the alternative, the processormay be any conventional processor, controller, microcontroller, or statemachine. A processor may also be implemented as a combination ofcomputing devices, e.g., a combination of a DSP and a microprocessor, aplurality of microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

It is understood that any specific order or hierarchy of steps in anydisclosed process is an example of a sample approach. Based upon designpreferences, it is understood that the specific order or hierarchy ofsteps in the processes may be rearranged while remaining within thescope of the present disclosure. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

In one or more exemplary embodiments, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media. It should beappreciated that a computer-readable medium may be implemented in anysuitable computer-program product.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present disclosure.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other aspects without departing from the scope of thedisclosure. Thus, the present disclosure is not intended to be limitedto the aspects shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A method of communication, comprising: selectinga cell advertising a closed subscriber group, wherein selecting the cellcomprises: scanning for available cells advertising at least one closedsubscriber group; displaying a list comprising at least one identifiercorresponding to the available cells advertising at least one closedsubscriber group; and selecting one of the available cells based on anindication from a user input device; identifying a public land mobilenetwork (PLMN) associated with the selected cell; switching from anautomatic mode of PLMN selection to a manual mode of PLMN selection as aresult of the identification of the PLMN; and registering at theidentified PLMN.
 2. The method of claim 1, wherein the switching isperformed as a result of a determination that the identified PLMN isdifferent than a currently registered PLMN.
 3. The method of claim 2,wherein: the identified PLMN comprises a visited PLMN; and the currentlyregistered network comprises a home PLMN.
 4. The method of claim 1,wherein the switching is performed as a result of a determination thatthe identified PLMN is different than a currently preferred PLMN.
 5. Themethod of claim 4, wherein: the identified PLMN comprises a visitedPLMN; and the currently preferred PLMN comprises a home PLMN.
 6. Themethod of claim 1, wherein: the automatic mode of PLMN selection isdefined to be used when camping on a macro cell; and the manual mode ofPLMN selection is defined to be used when camping on a closed subscribergroup cell.
 7. The method of claim 1, wherein the selection of the cellresults in camping on the cell, the method further comprising:maintaining a record of the automatic mode of PLMN selection;determining that the camping on the cell or camping on another cell ofthe closed subscriber group has ceased; and returning to the automaticmode of PLMN selection identified by the record based on thedetermination.
 8. The method of claim 7, further comprising selectingthe cell or another cell of the closed subscriber group for establishingcommunication if wireless coverage of the cell or the another cell isentered within a defined period of time after the determination thecamping on the cell or the another cell of the closed subscriber grouphas ceased.
 9. The method of claim 8, wherein the establishment ofcommunication comprises accessing the cell or the another cell orcamping on the cell or the another cell to receive at least one of thegroup consisting of: pages, data, and broadcast information.
 10. Anapparatus for communication, comprising: a cell selector configured toselect a cell advertising a closed subscriber group, wherein selectingthe cell comprises: scanning for available cells advertising at leastone closed subscriber group; displaying a list comprising at least oneidentifier corresponding to the available cells advertising at least oneclosed subscriber group; and selecting one of the available cells basedon an indication from a user input device; a network selector configuredto identify a public land mobile network (PLMN) associated with theselected cell, and further configured to switch from an automatic modeof PLMN selection to a manual mode of PLMN selection as a result of theidentification of the PLMN; and a communication controller configured toregister at the identified PLMN.
 11. The apparatus of claim 10, whereinthe switching is performed as a result of a determination that theidentified PLMN is different than a currently registered PLMN.
 12. Theapparatus of claim 11, wherein: the identified PLMN comprises a visitedPLMN; and the currently registered network comprises a home PLMN. 13.The apparatus of claim 10, wherein: the selection of the cell results incamping on the cell; the network selector is further configured tomaintain a record of the automatic mode of PLMN selection; thecommunication controller is further configured to determine that thecamping on the cell or camping on another cell of the closed subscribergroup has ceased; and the network selector is further configured toreturn to the automatic mode of PLMN selection identified by the recordbased on the determination.
 14. An apparatus for communication,comprising: means for selecting a cell advertising a closed subscribergroup, wherein the means for selecting the cell comprises: means forscanning for available cells advertising at least one closed subscribergroup; means for displaying a list comprising at least one identifiercorresponding to the available cells advertising at least one closedsubscriber group; and means for selecting one of the available cellsbased on an indication from a user input device; means for identifying apublic land mobile network (PLMN) associated with the selected cell;means for switching from an automatic mode of PLMN selection to a manualmode of PLMN selection as a result of the identification of the PLMN;and means for registering at the identified PLMN.
 15. The apparatus ofclaim 14, wherein the switching is performed as a result of adetermination that the identified PLMN is different than a currentlyregistered PLMN.
 16. The apparatus of claim 15, wherein: the identifiedPLMN comprises a visited PLMN; and the currently registered networkcomprises a home PLMN.
 17. The apparatus of claim 14, wherein: theselection of the cell results in camping on the cell; the apparatusfurther comprises means for maintaining a record of the automatic modeof PLMN selection; the apparatus further comprises means for determiningthat the camping on the cell or camping on another cell of the closedsubscriber group has ceased; and the means for switching is configuredto return to the automatic mode of PLMN selection identified by therecord based on the determination.
 18. A computer-program product,comprising: a non-transitory computer-readable medium comprising codefor causing a computer to: select a cell advertising a closed subscribergroup, wherein selecting the cell comprises: scanning for availablecells advertising at least one closed subscriber group; displaying alist comprising at least one identifier corresponding to the availablecells advertising at least one closed subscriber group; and selectingone of the available cells based on an indication from a user inputdevice; identify a public land mobile network (PLMN) associated with theselected cell; switch from an automatic mode of PLMN selection to amanual mode of PLMN selection as a result of the identification of thePLMN; and register at the identified PLMN.
 19. The computer-programproduct of claim 18, wherein the switching is performed as a result of adetermination that the identified PLMN is different than a currentlyregistered PLMN.
 20. The computer-program product of claim 19, wherein:the identified PLMN comprises a visited PLMN; and the currentlyregistered network comprises a home PLMN.
 21. The computer-programproduct of claim 18, wherein: the selection of the cell results incamping on the cell; the computer-readable medium further comprises codefor causing the computer to maintain a record of the automatic mode ofPLMN selection; the computer-readable medium further comprises code forcausing the computer to determine that the camping on the cell orcamping on another cell of the closed subscriber group has ceased; andthe computer-readable medium further comprises code for causing thecomputer to return to the automatic mode of PLMN selection identified bythe record based on the determination.
 22. The method of claim 1,wherein the switching from the automatic mode to the manual mode occursin response to a user manually selecting the closed subscriber group.